Striking mechanism for clocks



2 Sheets-Sheet 1.

(ModeL) A. E. HOTOHKISS. Striking Mechanism for Clocks.

Patented Feb. 8,1881

' INVEN'I'OR (Luck, (if) Mvvv ATTORNEY N.PETERS. PflOTO-LITMQGRAPMER. WASHDGGTON. D. C.

2 Sheets-Sheet 2.

(Model) A. E. HOTOHKISS. Striking Me0hanism'f0r01o 0ks.

INVENTOR {PM} TTORNEY N. PETERS, PHOTD-UTHOGRAPHER, WASHINGTOPLJ C.

UNITE STATES PATENT Crrrcne ARTHUR E. HOTCHKISS, OF CHESHIRE, CONNECTICUT.

STRIKING MECHANISM FOR GLOCK SPECIFICATION forming part of Letters Patent No. 237,532, dated February 8, 1881. Application filed September 13, 1880. (Model) To all whom it may concern Be it known that I, ARTHUR E. HOTOHKISS,

of Cheshire, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Striking Mechanism for Clocks; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being had to the accompanying drawings, which form part of this specification.

My invention relates to an improvement in striking mechanism for clocks.

Heretofore it has been practically impossible, for two reasons, to furnish small cheap clocks with any arrangement or construction of striking mechanism yet devised. First, the cost of the ordinary striking mechanism, and also its complex and delicate construction, preclude its employment on the small cheap clocks, which are in great demand by the trade; second, the contracted space within which the movement of this type of clocks must be placed will not allow of the employment of any of the ordinary kinds of striking attachments.

The object of my invention is to provide strikingmechanism forclock-movements which shall be of small initial cost and add but little to the cost of the clock, the mechanism to be simple and durable in construction and reliable in operation, and, further, adapted to be employed in the most compact space in a case, so as not to increase thesize or cost of the case.

With these ends in view my invention consists, essentially, in the combination, with a hammer and oscillating rack or ratchet plate for actuating thehammer, of a cam connected with the center shaft and adapted to raise the rack once every hour, and a cam connected with the hour-hand socket and adapted to regulate the descent of the rack and cause the latter to actuate the hammer the proper number of times to indicate the hour of the day.

My invention further consists in certain other details in constructionand combinations of parts, as will be hereinafter described, and

7 pointed out in the claims.

a plan view of a clock-movement provided with my improved striking mechanism, the parts being in their proper relative position just before the mechanism strikes one. Fig. 2 is a similar view of the parts just after the clock has struck one. Fig. 3 is a similar view, showing the relative position of parts just after the clock has struck twelve. Fig. 4 is an edge view of the movement. Fig. 5 shows an attachment for throwing the striking mechanism out of operation. Fig. 6 is a detached View of a device for allowing the hands to be turned backwardly without disarranging the strike mechanism. Fig. 7 is a modification.

A represents the front plate of a clock-movement. B is the center shaft, which is caused to make a complete revolution every hour by the well-known train of gearing. The front end of the center shaft is squared and drilled in the usual manner for the attachment of the minute-hand.

C is the hour-hand socket, which fits loosely upon the center shaft. Socket C has a wheel, a, staked thereon, which meshes with a pinion attached to the shaft 0, the latter being rotated by means of a wheel, 0, attached thereto, said wheel meshing with a pinion, 0 attached to the center shaft.

The parts described are of ordinary construction, and employed to impart a complete revolution to the hour-hand socket once every twelve hours, or one revolution to the hourhand socket for every twelve revolutions of the center shaft.

D is a segmental ratchet or rack plate, provided with teeth d, and having an arm, (1, which is pivoted upon a stud, d attached to the front plate, A, and held thereon by means of a washer and pin or in any other desired manner, whereby the ratchet or rack bar is free to oscillate.

E is a hammer, which is arranged to strike the bell F at proper intervals of time. Hammer-shaft G is attached to the pin or shaft g, journaled in the front plate, A, or in both'the front and back plates, and is provided on its end with two beveled projections, ff, which practically constitute a verge to regulate the descent of the ratchet-bar D.

To the shaft 9 is attached an arm, g, provided with counter-weight G, the latter being of less weight than the hammer, but serving to govern and regulate the movement thereof.

A spring, H, is attached at one end to the arm (1 of the segmental rack, the opposite end of the spring being secured to the stud h, or to any other fixed point on the front plate, the spring serving to draw the ratchet-bar downward.

To the center shaft is secured a cam, l, the periphery of which engages with a pin or stud, "5, attached to the arm (1 of the segmental rack or ratchet. The cam I, being attached to the center shaft, makes a complete revolution therewith once every hour, and thus serves to raise the ratchet or rack to the highest point of its travel once every hour.

To the hour-hand socket is secured a cam, K, the periphery of which is subdivided into twelve steps or faces, L, each being struck from the axis of the cam, but with gradual decreasing radii toward the axis.

Having described the construction and relative arrangement of parts of my improved striking mechanism, I will now give a brief description of its operation.

Fig.1 shows the relative position of the parts just before the mechanism strikes one. It will be observed that the pin or stud 2', attached to the arm of the segmental rack or ratchet, rests upon the periphery of the cam I near its point, the segmental rack having been raised by the cam during the last hour, so that the projection or palletf on the end of the hammer-shaft engages with the inclined face of the lower tooth of the ratchet bar or plate. As the cam I continues to revolve to the right the pin or stud i will be released therefrom at the hour of one and allow the ratchet-plate D to drop, which movement thereof is rendered certain by the action of the spring H. The distance through which the ratchet-plate D can travel is regulated by the cam K, and, as will be observed by reference to Fig. 2, said cam is in such position that the ratchet-plate can only drop a distance equal to the length of one of its teeth (I, as the pin or stud i strikes upon one of the twelve faces or steps of the cam K and prevents any farther descent of the ratchetplate. At the instant the stud i is released from the cam I and falls on the periphery of the cam K, the inclined facej of the lower tooth d of the segmental ratchet-plate, acting on the pallet or projection f of the hammer-shaft, operates to oscillate the latter on its pivotal bearing and raise the hammer. As the hammer is raised the pallet f engages with one of the ratchet-teeth and serves as a stop to prevent the sudden descent of the hammer. When the hammer has been raised a suflicient distance to release the pallet or projection j" from the lowest tooth on the rack or ratchet bar, the hammer falls and strikes the bell a single time to indicate the hour of one, and as the stud 'i on the arm of the segmental ratchet-plate engages with the periphery of the cam K, the ratchetplateis prevented from descending any farther, and consequently cannot again act on the hammer to raise and cause it to strike another blow. The cam I continues to revolve, and during the next succeedin hour again raises the segmental ratchet-plate to thehighest limit ofits travel, audits lowest tooth is in engagement with the pallet or proj ectionf on the end ofthe hammershaft. in order to allow of the rise of the segmental ratchet-bar, the pivotal bearing of the hammer-shaft is located in an inclined elongated slot, 7;, thus allowing the hammer-shaft to be moved laterally a slight distance when the ratchet-bar is raised and not interfere with the latter. \Vhen the end of the cam I comes under the pin or stud i at the second hour,the cam K will have then made one-twelfth of a revolution, thereby bringing the next face or step nearest the axis of the cam in proper position to receive and support the studt when released from cam I, and thus allow the ratchetplate to fall a distance equal to two of its teeth at the hour of two. As the ratchet-bar falls, or is positively depressed by its spring H, the ratchet-teeth will engage with the pallets on the end of the ham mer-shaft and actuate the hammer twice, or cause it to strike the bell twice, and indicate the hour of two. The operation of the striking mechanism thus continues as described. The cam I operates to raise the segmental ratchet-plate to a certain point at every revolution of the center shaft, while the descent of the ratchet-plate is graduated and regulated by the cam K.

Fig. 7 represents a modified form of construction. The hammer-shaft in this case is made of wire, having an eye, l, formed therein, which is placed over a stud, 1, attached to the front frame of the clock. The short arm l of the hammer-shaft has a pallet, m, formed thereon. Upon the stud 6 there is pivoted a pawl or dog, M, the end m being formed as a pallet, while the opposite end, m has alateral projection that engages the under side of the ham mer-shaft. As the ratchet-plate descends the teeth engage the pallet in on the pivoted dog or pawl M, and operate to raise the hammer-shaft; but when the ratchet-plate is raised the pawl M freely turns on its pivot and rides over the teeth of the ratchet-plate, and thus does not interfere with the ratchet-plate as it is being carried up to its highest position. That end of the pawl or dog upon which the pallet m is formed is made heavier than the other end, or a slight spring may be attached to the pawl in order to retain the pivoted pallet in proper position.

The time-train of the clock-movementis actuated either by a spring or weight. The spring or weight employed to run the time-train of a clock provided with my improvement also serves to store up power during every hour of the day to actuate the hammer, which is effected through the medium of the cam I raising the segmental ratchet in opposition to the tension of the spring H, and thereby allowing the latter to exert its power at the expiration of every hour in actuating the hammer and sounding the bell.

While I have shown and described a cam forraising the segmental ratchet, I may use any equivalent device for accomplishing the same result.

A wire may be attached to or connected with the center shaft or ti m e-train and adapted to raise the segmental ratchet. Again. the striking mechanism may be readily made to strike the half-hours by forming a notch in the cum I, said notch being located at about the center of the periphery of the cam, and thus allowing the ratchet to drop one tooth at every halfhour and sound the bell. This striking attachment may be applied to different kinds of clock movements, and also to watch-movements,if desired. \Vhile I have illustrated the bell as being applied to the side of the movement, it may be located beneath or within the movement. Again, instead ofattachiug the striking mechanism directly to the clock-movement, it may be made as a separate and distinct attachment, and be operated by suitable connections from the time-movement.

From the foregoing description it will be observed that the parts composing my improved striking mechanism are few in number, of simple, durable, and cheap construction, and may be attached to many different styles of movements.

In Fig. 5 I have represented an attachment for throwing the striking mechanism out of operation, when desired.

R is an arm attached to the shaft R, which is supported and free to rotate in bearings in the front and back plate of the clock-movement. On the rear end ot'the shaft It, which projects through a hole in the clock-case, is attached a button or knob, S, for rotating the shaft 1%. The arm R engages with a short arm, 0', attached to or formed as a continuation of the arm (1 of the segmental ratchet. By turning the button S in one direction the arm R is moved out of engagement with the arm r, and hence does not interfere with the operation ofthe striking mechanism. By turning the arm 1% in the opposite direction it operates to raise the segmental ratchet and retains it out of engagement with the cam by which it is operated, and thus prevents the striking mechanism from operatin This disengaging device is sometimes very desirableas, for instance, in the care of the sick it is sometimes necessary to prevent the clock from striking, which can be readily effected in the manner described. There are many ways by which I can accomplish the same result. A wire can be attached to the arm 1* and extend down below the movement, and, if desired, through the clock-case, and suitable fastening provided for securing the wire.

In Fig. 6 I have represented a device to allow of the hands being turned backward without disarranging the striking mechanism. On the arm (1 of the segmental ratchet I pivot, at t, aplate, T, the lower end of which engages with the cams for operating the striking mechanism. Plate T is provided with a shoulder, t which is held against a pin, t attached to the arm d by a slight spring, 2*. In the ordinary operation of the clock the lower end of plate T rides on the cams, and is retained against any movement, as the plate can move only in one direction. Should it be desired to turn the hands backward, the cams will strike and turn the plate T on its pivot, thus allowing its lower end to ride over the ends of both cams without disairanging the striking mechanism, because the strike mechanism always sets itself properly to correspond with the position ofthe hands. Many other forms of devices may be employed to allow the hands to be turned backward, and hence I do notlimit myself to that shown and described.

It is evident that many slight changes might be made in the construction and relative ar ran gement of parts without avoiding the spirit or scope of my invention, and hence I would have it understood that I do not restrict myself to the exact construction and relative arrangement of parts shown and described; but,

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The combination, with a hammer and an oscillating rack or ratchet provided with teeth which engage with the hammer-shaft and actuate the same the desired number of times to indicate the hours of the day, of a cam connected with the center shaftfor raising the rack or ratchet, and a cam connected with the hourhand socket for regulating the descent of the rack or ratchet, substantially as set forth.

2. The combination, with a segmental rack or ratchet provided with twelve or more teeth and ahammerengagingtherewith andadapted to be actuated thereby, of cams connected with the time-train for actuating thesegmental rack or ratchet and causing the hammers to strike the different hours of the day, substantially as set forth.

3. The combination, with a segmental rack or ratchet provided with twelve or more teeth and a hammer provided with pallets or projections which engage with the teeth of the segmcn tal rack or ratchet, ofcams connected with the time-train for actuating the segmental rack or ratchet and causing the hammer to strike the difi'erent hours of the day, substantially as set forth.

4. The combination, with a segmental ratchet and a hammer engaging therewith and adapted to be actuated thereby, of a cam engaging directly with the segmental ratchet and adapted to actuate it once every hour, and a graduated cam attached to the hour-hand socket and adapted to limit the movement of the ratchet, substantially as set forth.

5. The combination, with a segmental rack I or ratchet, of a hammer-shaft provided with pallets which engage the teeth of said ratchet or rack, one of said pallets adapted to be moved laterally to ride over the teeth of the rack or ratchet when the latter is raised, substantially as set forth.

6. The combination, with ahammer and segmental rack for actuating the hammer, of a cam connected with a time-train and revolved once every hour, and a cam connected with the time-train and revolved once every twelve hours, substantially as set forth.

7. The combination, with a stationary bell and a hammer engaging therewith, ofthe timetrain of a clock-movement and devices for actuating the hammer by the power imparted to the time-train, whereby the power of the time-train is utilized to indicate the time of day, and also to sound an alarm to properly indicate the different hours of the day, substantially as set forth.

8. The combination, with a stationary bell, a hammer and segmental rack provided with an arm, 4", of an adjustable arm, R, adapted to be engaged with the arm r of the segmental rack and throw the strike mechanism out of operative position at will, substantially as set forth.

9. The combination, with a rack or ratchet, a hammer engaging therewith and cams actuated by the time-train and adapted to operate the strike attachment, of a movable stop-pin connected with the ratchet or rack, whereby the hands may be turned backward without disarranging the strike mechanism, substantially as set forth.

In testimony that I claim the foregoing I have hereunto set my hand.

ARTHUR E. HOTCHKISS. \Nitnesses:

A. W. BRIGHT, CHAS. P. WEBs'rnR. 

